FIELD: radio engineering; demodulation of quadrature amplitude keying signals.
SUBSTANCE: signal undergoes following procedures: input signal is converted in first input-signal conversion unit followed by its low-frequency filtering; recovered frequency of quadrature amplitude keying signal (output signal of first controlled-voltage generator) is compared with reference oscillation (output signal of second controlled-voltage generator); in the process oscillations are compared directly and with 90° shift.
EFFECT: enhanced reliability of detection and elimination of false capture at operating signal-to-noise ratios.
1 cl, 1 dwg
